TiteGroup is a whole lot LESS well-behaved than AA2. It burns really hot and can produce pressure spikes. I MUCH prefer AA2.
Berry's are plated, so use lead bullet data. Get the Lyman manual (either standard or cast bullet manual).
124gn lead/plated and AA2: depending on the mix of components, my manuals have a start range of 3.7-4.1gn AA2 and a MAX range of 4.1-4.6gn. I would work up 3.7, 3.9, 4.1. That, in this case, is where I would stop, but, if there are no pressure signs, you could work up to 4.3 or 4.5gn.
For comparison, my manuals don't show TiteGroup loads at all for lead/plated (TiteGroup doesn't always play well with lead bullets), but jacketed data shows start loads of 3.3-4.1gn and MAX loads of 4.2-4.4gn. This is a bit narrower than with AA2.
With a plated bullet, you can usually work up from start to mid-range jacketed data, which would give you pretty much just the starting load range to work in: 3.3, 3.5, 3.7, 3.9, and 4.1gn.
All manuals used modern psi pressure data and all met SAAMI pressure specifications.
If you are shooting for accuracy, then get some Power Pistol, BE86, or Silhouette. If you are into action pistol shooting, I see absolutely no reason to change from AA2.